Embodiments of the present inventive concept are directed to a semiconductor device and, more particularly, to a semiconductor device that includes a capacitor.
As semiconductor devices have become more highly integrated, capacitors need to have a high capacitance in a limited area. The capacitance of a capacitor is proportional to a surface area of an electrode and a dielectric constant of a dielectric layer while being inversely proportional to an equivalent oxide thickness of the dielectric layer. Accordingly, to increase the capacitance of a capacitor within a limited area, the surface area of the electrode can be increased. In addition, the capacitance of the capacitor can be increased by reducing the equivalent oxide thickness of the dielectric layer or by using a dielectric layer having a high dielectric constant.
The surface area of the electrode can be increased by increasing the height of a lower electrode or a storage electrode, by increasing an effective surface area of the lower electrode using a hemi-spherical grain (HSG), or by increasing the inner and outer surface areas of a cylinder using a single cylinder storage (OCS) electrode.